<!DOCTYPE html>
<html>

<head>
  <meta charset="UTF-8" />
  <title>何为数据代理</title>
</head>

<body>
  <!-- 数据代理：通过一个对象代理对另一个对象中属性的操作（读/写）-->
  <script type="text/javascript">
    let obj = { x: 100 };
    let obj2 = { y: 200 };

    Object.defineProperty(obj2, "x", {
      get() {
        return obj.x;
      },
      set(value) {
        obj.x = value;
      }
    });
  </script>
</body>

</html>